diff options
Diffstat (limited to 'sys/vm/vm_fault.c')
| -rw-r--r-- | sys/vm/vm_fault.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/sys/vm/vm_fault.c b/sys/vm/vm_fault.c index d65cda2..909f57f 100644 --- a/sys/vm/vm_fault.c +++ b/sys/vm/vm_fault.c @@ -353,6 +353,15 @@ RetryFault:; KASSERT((fault_flags & VM_FAULT_WIRE) == 0, ("!wired && VM_FAULT_WIRE")); + /* + * Try to avoid lock contention on the top-level object through + * special-case handling of some types of page faults, specifically, + * those that are both (1) mapping an existing page from the top- + * level object and (2) not having to mark that object as containing + * dirty pages. Under these conditions, a read lock on the top-level + * object suffices, allowing multiple page faults of a similar type to + * run in parallel on the same top-level object. + */ if (fs.vp == NULL /* avoid locked vnode leak */ && (fault_flags & (VM_FAULT_WIRE | VM_FAULT_DIRTY)) == 0 && /* avoid calling vm_object_set_writeable_dirty() */ |
